Granule cell dispersion in the dentate gyrus of humans with temporal lobe epilepsy.

The distribution of granule cells in the dentate gyrus of the hippocampal formation was studied in control autopsy and temporal lobe epilepsy (TLE) specimens. In control tissue, the granule cell somata were closely approximated and formed a narrow lamina with a distinct, regular border with the molecular layer. In 11 of 15 TLE specimens, the granule cell somata were dispersed and formed a wider than normal granule cell layer. The granule cell somata extended into the molecular layer to varying extents, creating an irregular boundary between the lamina. The dispersed granule cells were frequently aligned in columns, and many of these neurons displayed elongated bipolar forms. The extent of granule cell dispersion appeared to be related to the amount of cell loss in the polymorph layer of the dentate gyrus. Granule cell dispersion was not consistently associated with granule cell loss although 5 of the 11 specimens with granule cell dispersion also showed moderate to marked granule cell loss. The most common features in the histories of the TLE cases with granule cell dispersion were severe febrile seizures or seizures associated with meningitis or encephalitis during the first 4 years of life. The dispersion of the granule cells suggests that there has been some alteration in the patterns of cell migration in a subpopulation of cases with severe TLE. The resultant ectopic positions of the granule cells could lead to changes in both the afferent and efferent connections of these neurons and, thus, contribute to the altered circuitry of the hippocampal formation in TLE.     

Aspirin: benefit and risk in thromboprophylaxis

Aspirin is often perceived either as a harmless panacea or as a useless poison which causes endless, needless trouble. We have carefully reviewed the literature on all aspects of aspirin and find that neither view is justified. Regular use of even low-dose aspirin (150 mg/day or less) may lead to clinically-important adverse events, particularly haemorrhage. The risk of such an event is considerably outweighed by the benefit for patients with a significant risk of a thromboembolic event. For individuals without a clear risk of thrombosis or thromboembolism, the balance is more even: indiscriminate aspirin- taking is to be discouraged.      

Transforming growth factor-β (TGF-β) activity in urine of patients with glomerulonephritis is related to their renal functional and structural changes

Transforming growth factor-β (TGF-β) has been considered the principal cytokine involved in the pathogenesis of renal fibrosis. In the present study, we evaluated TGF-β activity in occasional samples from 22 normal individuals and 29 patients (11 with focal glomerulosclerosis, 11 with membranous nephropathy, five with Berger disease, one with type I membranoproliferative glomerulonephritis and one with postinfectious glomerulonephritis) using a CCL-64 mink lung cell growth inhibition assay.
A significantly increased urinary TGF-β activity (reported in relation to urine creatinine, Ucreat. and median) was observed in patients with glomerulonephritis compared with normal individuals ( P <0.01). The patients with Berger disease [median (Md)=9.96/10 μg Ucreat.], membranous glomerulonephritis (Md=7.23/10 μg Ucreat.) and focal glomerulosclerosis (Md=16.6/10 μg Ucreat.) showed higher urinary TGF-β than normal individuals (Md=1.09/10 μg Ucreat.) ( P <0.01). We found a positive correlation between the TGF-β activity in the urine of these patients and the incidence of segmental glomerulosclerosis ( r =0.45, P <0.05) and their plasma creatinine levels ( r =0.87, P <0.01). A negative correlation was observed between the TGF-β activity in the urine of these patients and their creatinine clearance ( r =−0.75, P <0.01).
Our data suggest that measurement of urinary TGF-β activity could be a useful non-invasive procedure for the evaluation of renal TGF-β production, permitting the assessment of prognosis and the evaluation of therapeutic efficacy in patients with renal disease.     

Experiments investigating cooperative types in humans: a complement to evolutionary theory and simulations

Unlike other species, humans cooperate in large, distantly related groups, a fact that has long presented a puzzle to biologists. The pathway by which adaptations for large-scale cooperation among nonkin evolved in humans remains a subject of vigorous debate. Results from theoretical analyses and agent-based simulations suggest that evolutionary dynamics need not yield homogeneous populations, but can instead generate a polymorphic population that consists of individuals who vary in their degree of cooperativeness. These results resonate with the recent increasing emphasis on the importance of individual differences in understanding and modeling behavior and dynamics in experimental games and decision problems. Here, we report the results of laboratory experiments that complement both theory and simulation results. We find that our subjects fall into three types, an individual's type is stable, and a group's cooperative outcomes can be remarkably well predicted if one knows its type composition. Reciprocal types, who contribute to the public good as a positive function of their beliefs about others' contributions, constitute the majority (63%) of players; cooperators and free-riders are also present in our subject population. Despite substantial behavioral differences, earnings among types are statistically identical. Our results support the view that our human subject population is in a stable, polymorphic equilibrium of types.     

Use of a validated model to evaluate the impact of the work environment on outcomes at a magnet hospital

Using a structural model, we evaluated the impact of leadership, staff stability, resources, workload, work environment, and staff expertise on nurse-sensitive patient outcomes to determine elements that can be modified.